Ubuntu中设置分辨率时发现只有640x480和1024x768两个选项，在网上搜索了一下可以使用命令xrandr去设置，可是我执行该命令却出现了

“xrandr: Failed to get size of gamma for output default”

在网上看到了别人的解决办法，写一个配置文件然后重启就可以选择更多的分辨率了。摘取了原文一部分内容。原文地址点击打开链接

When I am trying to increase my Guest OS resolution to 1290X1080,while tried following steps mentioned HERE. Prior to that I was able to change the resolution by the above mentioned steps,but after a update to CENTOS 6.5 to 6.6,I am facing this error.Lots of people are having the same problem,but no solution I could not get my issue resolved.

I am able to get it solve to some extent by editing(creating) xorg.conf file in /etc/X11/,the file code I am sharing below

Section "Monitor" Identifier "Monitor0" VendorName "Monitor Vendor" ModelName "Monitor Model" HorizSync 28.0 - 70.0 VertRefresh 56.0 - 75.0 EndSection Section "Device" Identifier "VMware SVGA" Driver "vesa" EndSection Section "Screen" Identifier "Screen0" Device "Card0" Monitor "Monitor0" SubSection "Display" Viewport 0 0 Depth 24 Modes "1920x1080_60.00" EndSubSection EndSection 原文链接：https://www.f2er.com/ubuntu/355228.html